A building is an important basic element of an artificial target, and recognition of a building can be used in fields such as urban planning, supervision, aircraft navigation, and collision avoidance. The above-ground background is complex, and various buildings have different sizes and shapes. An imaging altitude and an imaging angle of a payload on a movement platform are variable. Therefore, recognition and positioning of an above-ground building are difficult tasks. Especially in navigation guidance of an aircraft at night time, when only infrared imaging is used, with three-dimensional range information of flight scenarios lacked, a navigation effect is undesirable in a complex ground object background.
At present, target recognition is mainly accomplished by performing digital processing on infrared imaging. However, in infrared imaging, range information is lacked and three-dimensional information of a target scenario cannot be directly obtained, therefore, a target recognition effect is undesirable in a complex background. In view of this, in current researches, attempts are generally made on improvements to aspects such as extraction of a line feature of a building target and multi-level perception and combination of line features. For example, in “BUILDING TARGET RECOGNITION METHOD IN COMPLEX SCENARIO” by M N Taisong, Y E Congying, L I Cuihua, et al. (Computer Engineering, Vol. 33, No. 6, March 2007), a method for searching, based on a vertical line feature of a building target, an image for a region in which a building target exists is proposed to improve accuracy of detection and recognition; however, because an infrared image does not include range information and information about a three-dimensional structure of a target, the improvement effect is always limited.